Communication method, system, and program

ABSTRACT

A communication method between service modules in a system in which service modules operating on a plurality of information processing apparatuses connected with a network operate in collaboration with each other, the system includes a monitoring apparatus that is provided with a monitor module monitoring a connection between service modules in the system and that has connection management information including identifier information for uniquely identifying an information processing apparatus in which a service module is operating in the system, and connection information including external connection information for the service module to perform communication using an external network between the information processing apparatuses and internal connection information for the service module to perform communication using an internal network of the information processing apparatus.

TECHNICAL FIELD

The present invention relates to a communication method betweeninformation processing apparatuses in a system in which a plurality ofnetwork-connected information processing apparatuses operate incollaboration with each other, and particularly to a communicationmethod between service modules in a virtualization environment.

BACKGROUND ART

With developments in server virtualization technology, server systeminfrastructures constructed using virtualization technology areincreasing. The server virtualization is a technology for causing asingle physical server (physical host) to operate as a plurality ofindependent servers, and is capable of causing a plurality ofindependent logical operating systems (OS) to run on a single physicalhost. Such logical operating systems are referred to as virtual machines(or guest OS). Typical examples of the virtualization technology includeMicrosoft's Hyper-V and Vmware's Vmware®. This virtualization technologyis utilized in cloud computing.

There are roughly two types of network configuration for thevirtualization environment. One is a network capable of communicationbetween virtual machines operating on the same physical host, which isreferred to as an internal network. The other is a network capable ofcommunication between virtual machines operating on different physicalhosts, which is referred to as an external network. Each virtual machinecan be provided with one or more virtual network interface cards (NIC),in which the use of either the internal network or the external networkis determined.

Conventional systems that operate in the virtualization environmentemploy the external network to perform communication betweenapplications running on virtual machines. This is because a system canrarely be constructed in which applications, a database server, a printserver and the like in the system all run on a single physical host.

In the external network, a virtual network is bound to a physical NICprovided in the physical host, and all network traffic is routed throughthe physical NIC. Accordingly, communication between virtual machinesthat use the external network is performed via the physical NIC. In thecase of using the external network, for example, in a high-volumeprinting system used to implement the core business of an enterprise, alarge amount of data needs to be exchanged between applications, whichconsumes resources of the physical NIC. This tendency appears moresignificantly as the number of virtual machines operating on the samephysical host increases because the physical NIC is shared by aplurality of virtual machines. Consequently, communication delays occurin the high-volume print processing.

As a specific example of a communication delay, a case has been reportedin which the time required to transfer a large amount of files betweenvirtual machines operating on the same physical host was approximatelyone hour using the internal network, but 8 hours using the externalnetwork. Aside from communication delays, there is a possibility that,in some cases, errors might occur in parts of the processing due tocommunication timeout.

As a conventional technique regarding a communication path betweenapparatuses, for example, Japanese Patent Laid-Open No. 2000-209278discloses a method in which communication is performed between twocommunication apparatuses by using a plurality of communication paths.As a conventional technique for selectively using communication paths,for example, a technique has been proposed in which two physical NICsare mounted on a server (physical host), one of the NICs is used forcommunication with a client, and data shared between servers is placedin storage connected to the other NIC (Oracle Real Application Clusters,[online], Oracle Corporation, April, 2007, Internet, <URL:

http://www.oracle.com/lamg/jp/database/rac_home.html, for example).

However, the conventional techniques have been designed to operate in anenvironment in which the virtualization technology is not used, and thushave a problem in that selective use of the external network and theinternal network is not possible in the virtualization environment.Japanese Patent Laid-Open No. 2000-209278 enables a connection to a widearea network (WAN) from a terminal in a local area network (LAN), andcan be applied only to the external network in the virtualizationenvironment. With Oracle Real Application Clusters, [online], OracleCorporation, April, 2007, Internet, <URL:

http://www.oracle.com/lamg/jp/database/rac_home.html>, the internalnetwork can be used only when the server and database server that sharedata operate on the same physical host, but otherwise, the externalnetwork is used.

In a system in which a large amount of data needs to be exchangedbetween applications by using the external network, resources of thephysical NIC are consumed, causing communication delays, and in somecases communication errors. Because a plurality of virtual machinesshare the physical NIC, the possibility of the occurrence ofcommunication delays and communication errors increases as the number ofvirtual machines operating on the same physical host increases.

For this reason, selective use of communication paths is necessary suchas using the internal network to perform communication between virtualmachines on the same physical host and using the external network toperform communication between virtual machines operating on differentphysical hosts.

SUMMARY OF INVENTION

According to one aspect of the present invention, there is provided acommunication method between service modules in a system in whichservice modules operating on a plurality of information processingapparatuses connected with a network operate in collaboration with eachother, the system including a monitoring apparatus that is provided witha monitor module monitoring a connection between service modules in thesystem and that has connection management information includingidentifier information for uniquely identifying an informationprocessing apparatus in which a service module is operating in thesystem, and connection information including external connectioninformation for the service module to perform communication using anexternal network between the information processing apparatuses andinternal connection information for the service module to performcommunication using an internal network of the information processingapparatus, the method comprising the steps of: acquiring, withconnection management information acquiring means of the informationprocessing apparatus, the connection management information from themonitor module; acquiring, with connection information acquiring meansof the information processing apparatus, connection information of acommunication destination service module from the acquired connectionmanagement information; comparing, with comparing means of theinformation processing apparatus, the identifier information of theinformation processing apparatus in which the service module isoperating and identifier information of an information processingapparatus in which the communication destination service module isoperating; and deciding, with deciding means of the informationprocessing apparatus, which of the internal connection information andthe external connection information included in the connectionmanagement information to use based on a result obtained in thecomparing step, wherein the deciding step decides to use the internalconnection information to perform communication with the communicationdestination service module using the internal network if it isdetermined in the comparing step that the identifier information itemsmatch each other, and decides to use the external connection informationto perform communication with the communication destination servicemodule using the external network if it is determined in the comparingstep that the identifier information items do not match each other.

According to another aspect of the present invention, there is provideda communication method between service modules in a system in whichservice modules operating on a plurality of information processingapparatuses connected with a network operate in collaboration with eachother, the system including a monitoring apparatus that is provided witha monitor module monitoring a connection between service modules in thesystem and that has connection management information includingidentifier information for uniquely identifying an informationprocessing apparatus in which a service module is operating in thesystem and connection information including external connectioninformation for the service module to perform communication using anexternal network between the information processing apparatuses andinternal connection information for the service module to performcommunication using an internal network of the information processingapparatus, the method comprising the steps of: acquiring, withconnection management information acquiring means of the informationprocessing apparatus, the connection management information from themonitor module; acquiring, with connection information acquiring meansof the information processing apparatus, connection information of acommunication destination service module from the acquired connectionmanagement information; comparing, with comparing means of theinformation processing apparatus, the identifier information of theinformation processing apparatus in which the service module isoperating and identifier information of an information processingapparatus in which the communication destination service module isoperating; deciding, with deciding means of the information processingapparatus, which of the internal connection information and the externalconnection information included in the connection management informationto use based on a result obtained in the comparing step, determining,with determining means of the information processing apparatus, whetheror not a connection to the communication destination service module inthe network has been established successfully using the connectioninformation; and notifying, with notifying means of the informationprocessing apparatus, the monitor module of a result of the connectionto the communication destination service module, wherein the decidingstep makes a change to use the external connection information if thedeciding step has decided to use the internal connection information andthe determining step has determined that the connection has failed, andthe notifying step notifies the monitor module that the communicationdestination service module has moved from a host in which thecommunication destination service module is operating if a connectionhas been established successfully using the external connectioninformation.

According to another aspect of the present invention, there is provideda system including a plurality of information processing apparatuses inwhich service modules that operate in collaboration with a monitoringapparatus provided with a monitor module operate, wherein the monitoringapparatus has connection management information including identifierinformation for uniquely identifying an information processing apparatusin which a service module is operating in the system and connectioninformation including external connection information for the servicemodule to perform communication using an external network between theinformation processing apparatuses and internal connection informationfor the service module to perform communication using an internalnetwork of the information processing apparatus, the informationprocessing apparatus comprises: connection management informationacquiring means for acquiring the connection management information fromthe monitor module; connection information acquiring means for acquiringconnection information of a communication destination service modulefrom the acquired connection management information; comparing means forcomparing the identifier information of the information processingapparatus in which the service module is operating and identifierinformation of an information processing apparatus in which thecommunication destination service module is operating; and decidingmeans for deciding which of the internal connection information and theexternal connection information included in the connection managementinformation to use based on a result obtained from the comparing means,and the deciding means decides to use the internal connectioninformation to perform communication with the communication destinationservice module using the internal network if the comparing means hasdetermined that the identifier information items match each other, anddecides to use the external connection information to performcommunication with the communication destination service module usingthe external network if the comparing means has determined that theidentifier information items do not match each other.

According to another aspect of the present invention, there is provideda program that causes a computer to function as: connection managementinformation acquiring means for acquiring connection managementinformation from a monitor module; connection information acquiringmeans for acquiring connection information of a communicationdestination service module from the acquired connection managementinformation; comparing means for comparing identifier information of aninformation processing apparatus in which a service module is operatingand identifier information of an information processing apparatus inwhich the communication destination service module is operating; anddeciding means for deciding which of internal connection information andexternal connection information included in the connection managementinformation to use based on a result obtained from the comparing means,wherein the deciding means decides to use the internal connectioninformation to perform communication with the communication destinationservice module using an internal network if the comparing means hasdetermined that the identifier information items match each other, anddecides to use the external connection information to performcommunication with the communication destination service module using anexternal network if the comparing means has determined that theidentifier information items do not match each other.

According to the present invention, it is possible to achieve selectiveuse of an external network and an internal network in a virtualizationenvironment. Furthermore, even in a system in which a large amount ofdata needs to be exchanged between applications such as a high-volumeprinting system, it is possible to suppress communication delays andcommunication errors. It is also possible to improve the processingspeed as compared to the case of using only the external network.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing a network configuration according to anembodiment of the present invention.

FIGS. 2A and 2B are diagrams showing hardware configurations accordingto the embodiment of the present invention.

FIG. 3 is a diagram showing a module configuration of web browsers andweb servers according to the embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a monitoring servicemodule according to the embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of a document managementservice module according to the embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of a print service moduleaccording to the embodiment of the present invention.

FIG. 7 shows an example of a configuration of a connection managementtable according to the embodiment of the present invention.

FIGS. 8A and 8B show examples of configurations of tables included in adatabase according to the embodiment of the present invention.

FIGS. 9A and 9B are flowcharts illustrating document management serviceprocessing according to a first embodiment.

FIGS. 10A and 10B are flowcharts illustrating print service processingaccording to the first embodiment.

FIG. 11 shows an example of an ARP table according to a secondembodiment.

FIGS. 12A and 12B are flowcharts illustrating document managementservice processing according to the second embodiment.

FIG. 13 is a flowchart illustrating monitoring service processingaccording to the second embodiment.

FIG. 14 is a flowchart illustrating print service processing accordingto the second embodiment.

FIG. 15 is a flowchart illustrating monitoring service processingaccording to the second embodiment.

DESCRIPTION OF EMBODIMENTS First Embodiment

Hereinafter, embodiments for carrying out the present invention will bedescribed with reference to the accompanying drawings. FIG. 1 is a blockdiagram showing a system configuration according to the presentembodiment. In FIG. 1, a network 100 connects constituent elements. Inother words, the constituent elements are network-connected by thenetwork 100. A client 101 issues requests to a web server 102. The webserver 102 receives requests from the client 101. A monitoring server104 monitors the states of document servers 106 and 109 and the statesof print servers 107 and 110. The document servers 106 and 109 processrequests received by the web server 102. The print servers 107 and 110receive documents from the document servers 106 and 109 and performprint processing.

A print apparatus 111 receives print jobs from the print servers 107 and110 and makes printouts. Host computers 103, 105 and 108 indicatephysical host computers. In a single physical host computer 105, twological operating systems (virtual machines) have been created using avirtualization technique, and the document server 106 and the printserver 107 are operating on the respective logical operating systems.The above-described constituent elements are connected by the network100 so as to be capable of communication with each other. Communicationis performed using, as communication means, communication protocols suchas HTTP and SOAP over HTTP, in other words, web services, as well asTCP/IP intercommunication. In the present invention, the physical hostcomputers are hereinafter referred to as physical hosts. Likewise, thelogical operating systems created on each physical host are referred toas “virtual machines”. In the present embodiment, service modules (orsoftware modules) are referred to simply as services. The presentembodiment is applicable to cloud computing.

System Configuration

FIG. 2A is a block diagram showing a hardware configuration of theclient 101, the web server 102, the monitoring server 104, the documentservers 106 and 109, and the print servers 107 and 110 shown in FIG. 1.A CPU 21 directly or indirectly controls devices (ROM 22, RAM 23 and thelike described later) connected via an internal bus, and executes aprogram for implementing the present invention. The ROM 22 stores a BIOSand the like. The RAM (direct storage device) 23 is utilized as a workarea by the CPU 21 or as a temporary storage for loading softwaremodules for implementing the present invention. A hard disk drive (HDD)24 is an indirect storage device, such as a HDD or an SSD (solid statedrive), in which basic software (OS) and software modules are stored. Aninput device 25 is a keyboard, a pointing device or the like. An outputdevice 26 is a display or the like. Interfaces (I/F) 27 and 28 arenetwork interface cards (NIC) or the like, and connection to the network100 is made via the I/Fs.

With the hardware configuration, upon activation, the CPU 21 reads theBIOS stored in the ROM 22 and then executes the BIOS, thereby the OS isloaded from the HDD 24 into the RAM 23 so as to be capable of execution.The CPU 21 loads various software modules, which will be describedlater, from the HDD 24 into the RAM 23 as necessary according to theoperation of the OS, so as to be capable of execution. The softwaremodules are executed and operated by the CPU 21 in collaboration withthe above-described devices. The I/Fs 27 and 28 are connected to thenetwork 100, and controlled by the CPU 21 according to the operation ofthe OS, thereby implementing communication with the above-describedcommunication means. The functions of the above-described apparatuses(servers) are not limited to the functions given herein as long as theapparatuses can implement functions provided in ordinary informationprocessing apparatuses.

FIG. 2B is a block diagram showing a hardware configuration of thephysical host 105, as well as hardware configurations of the documentserver 106 and the print server 107 that operate on virtual machinescreated on the physical host 105. This applies to a hardwareconfiguration of the physical host 108 and those of the document server109 and the print server 110 that operate on virtual machines created onthe physical host 108. The hardware configurations of the documentserver 106 and the print server 107 are virtual hardware configurationscreated by virtualization technology. The I/Fs 27 and 28 in FIG. 2Bindicate virtual network interface cards (NIC) created by virtualizationtechnology. Hereinafter, such NICs are referred to as “virtual NICs”.The constituent elements are the same as those of FIG. 2A except forbeing virtual, and thus redundant descriptions are omitted here. In FIG.2B, an I/F 1201 is a physical network interface card (NIC) mounted onthe physical host, and is connected to the network 100. Hereinafter,such a physical NIC mounted on a physical host will be referred to as a“physical NIC”.

In FIG. 2B, a network 1202 is a virtual network capable of communicationwith a virtual machine operating on another physical host. Hereinafter,the virtual network (inter-physical host network) capable ofcommunication with a virtual machine running on another physical hostwill be referred to as an “external network”. The external network 1202is connected to the physical NIC 1201, and performs data exchangebetween virtual machines from the virtual NIC 27 via the physical NIC1201. A network 1203 is a virtual network capable of communicationbetween virtual machines operating on the same physical host.Hereinafter, the virtual network (intra-physical host network) capableof communication only between virtual machines running on the samephysical host will be referred to as an “internal network”. The internalnetwork 1203 is not connected to the physical NIC 1201, and enablesdirect communication between the virtual NICs 28 without via thephysical NIC 1201, as well as data exchange between the virtualmachines.

In the present embodiment, the services provided within the systeminclude a print service and a document management service, but thepresent embodiment is not limited thereto, and other services may beadded as necessary. Here, the present invention is applicable as long asan environment in which various services are operated on a virtualnetwork can be implemented.

Module Configuration

FIG. 3 is a configuration diagram of software modules that run onclients 101 and web servers 102. Each software module is stored in acorresponding HDD 24 shown in FIG. 2A, and loaded into a correspondingRAM 23 and executed by a corresponding CPU 21 as described earlier. Theclients 101 are provided with a web browser 31 as a user interfaceapplication. The web servers 102 include a web application server 32,and a document monitor application 33 is deployed in each webapplication server 32.

The document monitor application 33 is configured as a so-called webapplication on the web application server 32, and the client 101 canaccess the document monitor application 33 via the web browser 31. Thedocument monitor application 33 returns user interface information inresponse to a request from the web browser 31. The web browser 31renders and displays the user interface information obtained from thedocument monitor application 33. The displayed user interfaceinformation includes, for example, a document information list managedby a document management service, an interface for making a request toprint a document, and so on. The document monitor application 33 makes,to the document management service, a request to acquire a documentinformation list or print a document requested by the web browser 31.

FIG. 4 is a configuration diagram of a monitoring service module(monitor module) that runs on the monitoring server 104. Each softwaremodule is stored in the HDD 24 shown in FIG. 2A, and loaded into the RAM23 and executed by the CPU 21 as described earlier. A monitoring service40 monitors the status of a document management service 50 and a printservice 60, and executes processing such as failover depending on thestatus of each service. The monitoring service 40 receives requests fromthe document monitor application 33, the document management service 50and the print service 60, and returns connection information, which willbe described later. The monitoring service 40 is constituted by aninterface unit 401, a control unit 402, a table management unit 403 andan existence monitoring unit 404. The interface unit 401 processescommunication with other services. The control unit 402 executesprocessing according to received requests. The table management unit 403executes processing on a connection management table 41. The existencemonitoring unit 404 is a trigger for regularly monitoring the existencestate of each service. The monitoring service 40 executes processing,which will be described later, in collaboration with the constituentelements.

The interface unit 401 performs communication with the document monitorapplication 33, the document management service 50 and the print service60. The communication is executed by the CPU 21 shown in FIG. 2A via theI/Fs 27 and 28 according to the operation of the OS in response to theOS receiving an instruction from each software module. The connectionmanagement table 41 contains connection information for performingcommunication with the document management service 50 and the printservice 60. Connection information for each service is notified to themonitoring service 40 during kitting process in which each service isincorporated into the system, and the monitoring service 40 creates theconnection management table 41 based on the notified connectioninformation and stores the table on the HDD 24.

FIG. 5 is a configuration diagram of software modules that run on thedocument servers 106 and 109. Each software module is stored on the HDD24 shown in FIG. 2A, and loaded into the RAM 23 and executed by the CPU21 as described earlier. The document management service 50 receivesrequests from the document monitor application 33, and executes varioustypes of document processing. The document management service 50 isconstituted by an interface unit 501 that processes communication withother services, a control unit 502 that executes processing according toreceived requests, and a document data management unit 503 that executesprocessing on document data. A connection management table cache 504caches the connection management table 41 acquired from the monitoringserver 104. The connection management table cache 504 is stored in theRAM 23 shown in FIG. 2A. The interface unit 501 performs communicationwith the document monitor application 33, the monitoring server 104 andthe print servers 107 and 110. The communication is executed by the CPU21 shown in FIG. 2A via the I/Fs 27 and 28 according to the operation ofthe OS in response to the OS receiving an instruction from each softwaremodule.

A document management database 51 contains document data information.The document management database 51 is stored on the HDD 24 shown inFIG. 2A. The control unit 502 controls processing of each constituentunit of the document management service 50. When the interface unit 501receives a request to print a document from the document monitorapplication 33, the control unit 502 acquires the corresponding documentrecord from the document data management unit 503. The control unit 502also transmits the document data to the print server 107 or 110 via theinterface unit 501.

FIG. 6 is a configuration diagram of software modules that run on theprint servers 107 and 110. Each software module is stored on the HDD 24shown in FIG. 2A, and loaded into the RAM 23 and executed by the CPU 21as described earlier. The print service 60 is a print service thatreceives a document from the document management service 50 and causesthe print apparatus 111 to perform print processing. The print service60 includes an interface unit 601 that processes communication with thedocument management service 50 and the monitoring service 40. Thecommunication is executed by the CPU 21 shown in FIG. 2A via the I/Fs 27and 28 according to the operation of the OS in response to the OSreceiving an instruction from the interface unit 601. The print service60 is constituted by a control unit 602 that processes receivedrequests, and a print job management unit 603 that manages the progressof print jobs. A connection management table cache 604 caches theconnection management table 41 acquired from the monitoring server 104,and stores the table in the RAM 23 shown in FIG. 2A. A print jobdatabase 61 contains print job information, and is stored on the HDD 24shown in FIG. 2A.

The control unit 602 controls processing of each constituent unit of theprint service 60. The interface unit 601 receives documents from thedocument servers 106 and 109. The interface unit 601 also transmitsprint jobs to the print apparatus 111. The control unit 602 creates aprint job upon receiving a document from the document server 106 or 109,and transmits the print job to the print apparatus 111 via the interfaceunit 601. The control unit 602 waits for a notification containing printjob progress/result information from the print apparatus 111. When thecontrol unit 602 receives a notification containing print jobprogress/result information from the print apparatus 111, the print jobmanagement unit 603 updates the corresponding job record in the printjob table stored in the print job database 61. The print job managementunit 603 also sends a notification indicating the status to the documentserver 106 or 109.

Connection Management Table

FIG. 7 is a diagram showing a data structure of the connectionmanagement table 41, i.e., connection management information. Theconnection management table 41 includes service information 700 andprinter information 710. The service information 700 contains andmanages information regarding the document management service 50 and theprint service 60. The service information 700 includes a service ID 701,a service type 702, an external communication connection address 703, anexternal communication connection port 704, an internal communicationconnection address 705, an internal communication connection port 706,and a host identifying ID 707. The service ID 701 is a serviceidentifier. The service type 702 indicates the type of the service. Theexternal communication connection address 703 contains a connectionaddress for external network communication. The external communicationconnection port 704 contains a connection port number for externalnetwork communication. The internal communication connection address 705contains a connection address for internal network communication. Theinternal communication connection port 706 contains a connection portnumber for internal network communication. The host identifying ID 707is an identifier for identifying a physical host in which the service isrunning. The service type 702 is a region in which either the documentmanagement service 50 or the print service 60 is specified. The hostidentifying ID 707 contains information that can uniquely identify,within the network 100, a physical host in which the service is running,such as a host name, a FQDN address and a MAC address.

The printer information 710 contains and manages information regarding aprinter managed by the print service 60. The printer information 710includes a service ID 711, a registered printer name 712, a printeraddress 713, a printer port 714 for connecting to the printer, driverinformation 715, and a device model 716. The service ID 711 is anidentifier for identifying the print service 60 managing the printer.The printer address 713 indicates the location of the printer. Thedriver information 715 is information used to perform printing using themanaged printer. The device model 716 is the model name of the managedprinter. The service ID 711 is related to the service ID of the serviceinformation 700.

Data Configuration

FIG. 8A shows an example of a configuration of a table in the documentdatabase 51 managed by the document management service 50. A documenttable 801 is a table that holds documents, and this table includes aplurality of document records 802. Document identifying ID 803 is an IDfor uniquely identifying a document, and document name 804 is the nameof the document. Printer identification information 805 is informationfor identifying the print apparatus 111 that performs print processing.As the identification information, an IP address, a host name and thelike of the image forming apparatus are used. Job type 806 is the typeof a description language of the saved job, such as PDL, PDF, and adocument description language.

Status 807 indicates the status of the document, and holds statusinformation indicating a state such as “waiting”, “printing”, “completedsuccessfully” and “completed with an error”. Reception date/time 808 isthe date and time at which the document was input to the documentmanagement service 50 and the document management service 50 saved thedocument in the document database 51. User ID 809 is information foridentifying an owner of the document. Document data 810 is the documentitself that has been input to the document management service 50.

FIG. 8B shows an example of a configuration of a table in the print jobdatabase 61 managed by the print service 60. A print job table 901 is atable that holds print job information, and this table includes aplurality of print job records 902. Job identifying ID 903 is an ID foruniquely identifying a print job. Document name 904 indicating the nameof the print job and status 905 holding the print state of the job arealso included.

The status 905 holds information indicating “printing” when the printapparatus 111 starts printing, and indicates the result of printing,such as “completed”, “interrupted” or the like, when printing isfinished. Reception date/time 907 is the date and time at which theprint service 60 received the print request. User ID 908 isidentification information indicating a user who made the print request(a user name, a user ID, a password, and the like), session informationgenerated by the web server 102, or the like.

Document Management Processing Procedure

Hereinafter, a processing procedure performed by each software module ofthe present invention will be described with reference to a flowchart.FIGS. 9A and 9B are flowcharts illustrating processing performed whenthe document management service 50 has received a print request from thedocument monitor application 33 of the web server 102. In thisspecification, the control unit 502 is made up of a CPU, a RAM, a ROM, aHDD and the like, and the procedure shown in the flowchart is stored inany of the RAM, the ROM and the HDD of the control unit 502, andexecuted by the CPU 21. In the present invention, it is assumed thatdocuments have already been saved in the document servers 106 and 109,and a request to print a specific document can be made from the documentmonitor application 33 of the web server 102.

Various methods are conceivable as a method for saving a document in thedocument servers 106 and 109, and the following method can be used, forexample. If a request to save a document has been received from anapplication that created the document, the monitoring service 40temporarily receives the request, and decides a save location based onthe user name of a user who made the document save request. Then, thedocument is transmitted to either of the document servers 106 and 109decided by the monitoring service 40. As a method for identifying adocument from the document monitor application 33, a method isconceivable in which either of the document servers 106 and 109 to beaccessed is decided based on the user name of a user who has logged inso as to acquire a document information list, and a document isidentified. However, the present invention is not limited to thismethod.

In S1001, the control unit 502 receives a print request from thedocument monitor application 33. Next, in S1002, the control unit 502determines whether the connection management table 41 has been acquiredfrom the monitoring service 40. If the connection management table 41has not been acquired, in S1003, the connection management table 41 isacquired from the monitoring service 40, and stored in the connectionmanagement table cache 504. Connection management information is therebyacquired.

Next, in S1004, the control unit 502 acquires, based on the name of aprinter where printing is carried out specified as a communicationdestination service in the print request, a service ID of the printservice 60 managing the printer from printer information 710 stored inthe connection management table cache 504. From the service ID specifiedas a communication destination service and service information 700, theprint service 60 managing the printer is specified. More specifically,the service ID 711 of the printer information 710 is specified from theprinter name, and service information 700 related to the service ID isacquired. The acquired information includes an external communicationconnection address 703, an external communication connection port 704,an internal communication connection address 705, an internalcommunication connection port 706, and a host identifying ID 707. Thecontrol unit 502 acquires, from the service information 700 stored inthe connection management table cache 504, an internal communicationconnection address 705, an internal communication connection port 706and a host identifying ID 707 of the document management service 50.Connection information is thereby acquired. The information acquiredhere are collectively referred to as connection information.

Next, in S1005, the control unit 502 determines whether the internalcommunication connection address 705 of the document management service50 and the internal communication connection address 705 of the printservice 60 specified as a communication destination service have beenregistered. If both internal communication connection addresses 705 havebeen registered, in S1006, the control unit 502 compares the hostidentifying ID 707 of the document management service 50 and the hostidentifying ID 707 of the specified print service 60 (communicationdestination service module), and determines whether or not they matcheach other. If it is determined in S1005 that either or both of theinternal communication connection addresses 705 have not beenregistered, control advances to S1007.

If it is determined in S1006 that the host identifying IDs 707 do notmatch each other, in S1007, the control unit 502 decides to use theexternal communication connection address 703 and the externalcommunication connection port 704 of the document management service 50serving as a sender. The control unit 502 also decides to use theexternal communication connection address 703 and the externalcommunication connection port 704 of the print service 60 serving as areceiver. If it is determined in S1006 that the host identifying IDs 707match each other, in S1008, the control unit 502 decides to use theinternal communication connection address 705 and the internalcommunication connection port 706 of the document management service 50serving as a sender. The control unit 502 also decides to use theinternal communication connection address 705 and the internalcommunication connection port 706 of the print service 60 serving as areceiver.

After processing of S1007 or S1008, in S1009, the control unit 502transmits a document to the print service 60. Subsequently, in S1010,the control unit 502 determines whether or not a notification has beenreceived from the print service. If it is determined in S1010 that astatus communication has been received from the print service 60, inS1011, the status of the corresponding document record in the documentdatabase 51 is updated. Then, in S1012, it is determined whether or notthe notified status indicates either “printing completed” or“cancellation completed”. If it is determined in S1012 that the notifiedstatus indicates either “printing completed” or “cancellationcompleted”, the processing procedure is finished. If it is determined inS1012 that the notified status indicates neither “printing completed” or“cancellation completed”, control returns to S1010, where the controlunit 502 waits for receipt of a notification. The document managementservice 50 executes print processing through the above procedure.

Print Service Processing

FIGS. 10A and 10B are flowcharts illustrating processing performed whenthe print service 60 has received a print request from the documentmanagement service 50. In the present embodiment, the control unit 602includes a CPU, a RAM, a ROM, a HDD and the like. The procedure shown inthe flowchart is stored in any of the storage units including the RAM,the ROM and the HDD of the control unit 602, and executed by the CPU 21.

In S1101, the control unit 602 receives a print request from thedocument management service 50. Then, in S1102, the control unit 602stores the sender address and port in the RAM 23. Next, in S1103, thecontrol unit 602 executes print processing. The print processingperformed here is ordinary processing, and thus a description thereof isomitted here.

Subsequently, in S1104, it is determined whether a change has been madeto the status of the print job. If it is determined in S1104 that achange has been made to the status of the print job, in S1105, thecontrol unit 602 updates the job identifying ID 903, the document name904 and the changed status 905 of the print job record.

Next, in S1106, the control unit 602 determines the changed status. Ifit is determined in S1106 that the status is “printing”, “cancellationcompleted” or “printing completed” (S1107, S1108 or S1109), controladvances to S1110. If it is determined in S1106 that the status is noneof “printing”, “cancellation completed” and “printing completed”,control returns to S1104. In S1110, the control unit 602 determineswhether the connection management table 41 has been acquired from themonitoring service 40. If the connection management table 41 has notbeen acquired, in S1111, the control unit 602 acquires the connectionmanagement table 41 from the monitoring service 40, and stores the tablein the connection management table cache 604. Next, in S1112, thecontrol unit 602 specifies the document management service 50, which isa sender, from the service information 700 in the connection managementtable cache 604 based on the sender address and port stored in the RAM23 in S1102. Next, the control unit 602 acquires the externalcommunication connection address 703, the external communicationconnection port 704, the internal communication connection address 705,the internal communication connection port 706 and the host identifyingID 707 of the document management service 50. The control unit 602 alsoacquires the internal communication connection address 705, the internalcommunication connection port 706 and the host identifying ID 707 of theprint service 60 from the service information 700 in the connectionmanagement table cache 604.

Next, in S1113, the control unit 602 determines whether or not theinternal communication connection address 705 of the print service 60and the internal communication connection address 705 of the specifieddocument management service 50 have been registered. If both internalcommunication connection addresses 705 have been registered, in S1114,the control unit 602 compares the host identifying ID 707 of the printservice 60 and the host identifying ID 707 of the specified documentmanagement service 50 (communication destination service module), anddetermines whether or not they match each other. If it is determined inS1113 that either or both of the internal communication connectionaddresses 705 have not been registered, control advances to S1115.

If it is determined in S1114 that the host identifying IDs 707 do notmatch each other, in S1115, the control unit 602 decides to use theexternal communication connection address 703 and the externalcommunication connection port 704 of the print service 60 serving as asender. The control unit 602 also decides to use the externalcommunication connection address 703 and the external communicationconnection port 704 of the specified document management service 50serving as a receiver. If it is determined in S1114 that the hostidentifying IDs 707 match each other, in S1116, the control unit 602decides to use the internal communication connection address 705 and theinternal communication connection port 706 of the print service 60serving as a sender. The control unit 602 also decides to use theinternal communication connection address 705 and the internalcommunication connection port 706 of the specified document managementservice 50 serving as a receiver.

Then, after processing of S1115 or S1116, in S1117, the control unit 602sends a notification indicating the status determined in S1107, S1108 orS1109 to the specified document management service 50. The print service60 executes print processing upon receiving a print request from thedocument management service 50 through the above procedure.

With the above configuration, it is possible to achieve selective use ofan external network and an internal network in a virtualizationenvironment. It is also possible to suppress communication delays andcommunication errors even in a system that requires exchange of a largeamount of data between applications such as a high-volume printingsystem. It is also possible to improve the processing speed as comparedto the case where the external network is used.

Second Embodiment

The first embodiment has been described in the context of the physicalhosts in which virtual machines are running being fixed. As an importantfunction in the virtualization technique, there is a function of causinga virtual machine to move from its physical host in which the virtualmachine is running while continuing its service without stopping thevirtual machine. This function is called “live migration”. The livemigration enables increasing the availability of the system. In a statusin which an internal network is used for communication between services,if one of the virtual machines has moved from its host by the livemigration, the communication between services will be halted. Thepresent embodiment enables communication between services even when thelive migration is performed, so that the internal network can be usedfor communication with a virtual machine running on a physical host towhich the virtual machine has moved.

Document Management Service Processing

FIGS. 12A and 12B are flowcharts illustrating processing performed bythe document management service 50 upon receiving a print request fromthe document monitor application 33 of the web server 102. In thepresent embodiment, the control unit 502 includes a CPU, a RAM, a ROM, aHDD and the like. The procedure shown in the flowchart is stored in anyof the storage units including the RAM, the ROM and the HDD of thecontrol unit 502, and executed by the CPU 21. The procedure issubstantially the same as that described in the first embodiment withreference to FIGS. 9A and 9B, and thus only differences will bedescribed below.

In S1408 (corresponding to S1008 of FIG. 9A), the control unit 502decides to use the internal communication connection address 705 and theinternal communication connection port 706 of the document managementservice 50 serving as a sender. The control unit 502 also decides to usethe internal communication connection address 705 and the internalcommunication connection port 706 of the print service 60 serving as areceiver. Next, the control unit 502 attempts a connection to the printservice 60.

Subsequently, in S1413, the control unit 502 determines whether or not aconnection to the print service 60 has been established successfully. Ifit is determined that the connection has been established successfully,control advances to S1409. If it is determined that the connection hasfailed, in S1414, the control unit 502 decides to use the externalcommunication connection address 703 and the external communicationconnection port 704 of the document management service 50 serving as asender. The control unit 502 also decides to use the externalcommunication connection address 703 and the external communicationconnection port 704 of the print service 60 serving as a receiver. Next,the control unit 502 attempts a connection to the print service 60.

Next, in S1415, the control unit 502 determines whether or not aconnection to the print service 60 has been established successfullybased on the information decided in S1414. If it is determined that theconnection has failed, in S1416, the control unit 502 waits until theprint service 60 is restored. The connection failure in S1415 indicatesthat the print service 60 is not available for some reasons, that is,the print service 60 will be restored sometime soon through execution offailover. For example, the monitoring service 40 may perform thefailover.

If it is determined in S1415 that the connection has been establishedsuccessfully, in S1417, the control unit 502 sends a notificationindicating that the print service 60 has moved from the physical hosttogether with the service ID 701 of the print service 60 to themonitoring service 40. Then, control advances to S1409 (corresponding toS1009 of FIG. 9B). In the present embodiment, in S1416, a configurationis employed in which the control unit 502 waits until the print service60 is restored, but the processing may be finished as an error.Alternatively, at this time, the information decided in S1414 may bechanged from the external connection information to the internalconnection information decided in S1408.

Monitoring Service Processing

FIG. 13 is a flowchart illustrating processing performed by themonitoring service 40 upon receiving a notification indicating that theprint service 60 has moved from the physical host from the documentmanagement service 50. In the present embodiment, the control unit 402includes a CPU, a RAM, a ROM, a HDD and the like. The procedure shown inthe flowchart is stored in any of the storage units including the RAM,the ROM and the HDD of the control unit 402, and executed by the CPU 21.

In S1501, the control unit 402 receives a notification indicating thatthe print service 60 has moved from the physical host. Then, in S1502,the control unit 402 specifies the print service 60 from the serviceinformation 700 in the connection management table 41 based on theservice ID 701 sent together with the notification. Subsequently, thecontrol unit 402 updates the connection management table 41 by deletingthe internal communication connection address 705, the internalcommunication connection port 706 and the host identifying ID 707 of theprint service 60. Then, in S1503, the control unit 402 sends, to allservices, a notification of the internal communication connectionaddress 705 and the host identifying ID 707 of the print service 60together with the service ID 701 of the print service 60, and instructsthem to update the connection information.

Print Service Processing

FIG. 14 is a flowchart illustrating processing performed by the printservice 60 upon receiving an instruction to update the internalconnection information from the monitoring service 40. In the presentembodiment, the control unit 602 includes a CPU, a RAM, a ROM, a HDD andthe like. The procedure shown in the flowchart is stored in any of thestorage units including the RAM, the ROM and the HDD of the control unit602, and executed by the CPU 21.

In S1601, the control unit 602 receives an instruction to update theinternal connection information. Then, in S1602, the control unit 602determines whether the instruction is an instruction for the printservice 60 based on the service ID 701. If it is determined in S1602that the instruction is not an instruction for the print service 60,control returns to S1601, where the control unit 602 waits until thenext instruction is received. If it is determined that the instructionis an instruction for the print service 60, in S1603, the control unit602 acquires an ARP table from a router/switching hub or the likeconnected to the network 100. Most network devices such as arouter/switching hub or the like hold a management information base(MIB), and are capable of acquiring information held by other networkdevices using a simple network management protocol (SNMP). In thepresent embodiment, the ARP table is acquired from a managed objectipNetToMediaTable of the standard MIB (MIB-2). FIG. 11 shows an exampleof an ARP table acquired. In FIG. 11, two IP addresses connect to a port1, and one IP address connects to a port 2. However, the configurationis not limited thereto, and other specifications may be used. Inaddition, besides the ARP table, the information may be acquired from adevice other than the network devices as long as correspondinginformation in which port information and information such as MACaddresses and IP addresses are associated with each other can beacquired. ps Corresponding information is thereby acquired.

In S1604, the control unit 602 searches the acquired ARP table for theexternal communication connection address 703 of the print service 60 toacquire an IP address connected to the same port as the externalcommunication connection address 703 of the print service 60. In S1605,the control unit 602 determines whether there is an IP address connectedto the same port as the external communication connection address 703 ofthe print service 60. If it is determined in S1605 that there is an IPaddress connected to the same port, control advances to S1606. If it isdetermined in S1605 that there is no IP address connected to the sameport, the processing procedure ends. In S1606, the control unit 602specifies the service of the IP address from the connection managementtable cache 604, and acquires connection information of the service.

Subsequently, in S1607, the control unit 602 determines whether or notan internal communication connection address 705 has been registered inthe connection information acquired in S1606. If it is determined inS1607 that an internal communication connection address 705 has beenregistered, in S1608, the control unit 602 calculates an IP address onthe same segment as the internal communication connection address 705,and sets the IP address in the virtual NIC of the print service 60. If,for example, the acquired internal communication connection address 705is “192.168.0.100”, “192.168.0.101” is calculated. If it is determinedin S1607 that an internal communication connection address 705 has notbeen registered, the processing procedure ends.

Subsequently, in S1609, the control unit 602 determines whether the IPaddress calculated in S1608 is used by other virtual machine. If it isdetermined that the calculated IP address is already used, controlreturns to S1608, another IP address is calculated. If it is determinedthat the calculated IP address is not used by other virtual machine, inS1610, the control unit 602 decides the IP address and the hostidentifying ID 707 acquired in S1606 as its own internal communicationconnection address 705 and host identifying ID 707. The control unit 602updates the connection management table cache 604. After S1610, inS1611, the control unit 602 sends a notification of its own internalcommunication connection address 705 and its own host identifying ID 707to the monitoring service 40 together with its own service ID 701.

Monitoring Service Processing

FIG. 15 is a flowchart illustrating processing performed by themonitoring service 40 upon receiving an internal connection informationdecision notification from the print service 60. In the presentembodiment, the control unit 402 includes a CPU, a RAM, a ROM, a HDD andthe like. The procedure shown in the flowchart is stored in any of thestorage units including the RAM, the ROM and the HDD of the control unit402, and executed by the CPU 21.

In S1701, the control unit 402 receives an internal connectioninformation decision notification from the print service 60. After that,in S1702, the control unit 402 specifies the print service 60 from theservice information 700 in the connection management table 41 based onthe service ID 701 sent together with the notification. Then, thecontrol unit 402 updates the connection management table 41 by using theinternal communication connection address 705 and the host identifyingID 707 sent together with the notification. After S1702, in S1703, thecontrol unit 402 sends, to all services, a notification of the printservice 60 together with the service ID 701 of the print service 60, andinstructs them to update the internal connection information. Updatenotification is thereby achieved.

With the above configuration, in addition to the effects of the firstembodiment, even when a virtual machine has moved by a live migration,communication between services can be continued. For communication withthe service operating on the destination physical host, the internalnetwork can be used. It is also possible to perform communicationbetween services by reducing the consumption of resources of thephysical NIC to the lowest level possible while increasing theavailability of the system by using the live migration.

Other Embodiments

Aspects of the present invention can also be realized by a computer of asystem or apparatus (or devices such as a CPU or MPU) that reads out andexecutes a program recorded on a memory device to perform the functionsof the above-described embodiments, and by a method, the steps of whichare performed by a computer of a system or apparatus by, for example,reading out and executing a program recorded on a memory device toperform the functions of the above-described embodiments. For thispurpose, the program is provided to the computer for example via anetwork or from a recording medium of various types serving as thememory device (e.g., computer-readable medium).

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2009-298835, filed on Dec. 28, 2009, which is hereby incorporated byreference herein in its entirety.

1. A communication method between service modules in a system in whichservice modules operating on a plurality of information processingapparatuses connected with a network operate in collaboration with eachother, the system including a monitoring apparatus that is provided witha monitor module monitoring a connection between service modules in thesystem and that has connection management information includingidentifier information for uniquely identifying an informationprocessing apparatus in which a service module is operating in thesystem, and connection information including external connectioninformation for the service module to perform communication using anexternal network between the information processing apparatuses andinternal connection information for the service module to performcommunication using an internal network of the information processingapparatus, the method comprising steps of: acquiring, with a connectionmanagement information acquisition unit of the information processingapparatus, the connection management information from the monitormodule; acquiring, with a connection information acquisition unit of theinformation processing apparatus, connection information of acommunication destination service module from the acquired connectionmanagement information; comparing, with a comparison unit of theinformation processing apparatus, the identifier information of theinformation processing apparatus in which the service module isoperating and identifier information of an information processingapparatus in which the communication destination service module isoperating; and deciding, with a decision unit of the informationprocessing apparatus, which of the internal connection information andthe external connection information included in the connectionmanagement information to use based on a result obtained in thecomparing step, wherein a decision is made in the deciding step to usethe internal connection information to perform communication with thecommunication destination service module using the internal network, ifa determination is made in the comparing step that the identifierinformation items match each other, and a decision is made in thedeciding step to use the external connection information to performcommunication with the communication destination service module usingthe external network, if a determination is made in the comparing stepthat the identifier information items do not match each other.
 2. Thecommunication method according to claim 1, further comprising a step ofdetermining, with a determination unit of the information processingapparatus, whether the connection management information has beenacquired, wherein, in the connection management information acquiringstep, the connection management information is acquired from the monitormodule, if a determination is made in the determining step that theconnection management information has not been acquired.
 3. Thecommunication method according to claim 1, further comprising a step ofmanaging, with a table management unit of the monitoring apparatus, theconnection management information, wherein, in the managing step, theconnection information is received from the service module and theconnection management information is updated.
 4. The communicationmethod according to claim 1, wherein in the connection managementinformation, the identifier information is a host identifying ID, andthe external connection information and the internal connectioninformation are IP address and port information.
 5. The communicationmethod according to claim 1, wherein the service module is a printservice module or a document management service module.
 6. Acommunication method between service modules in a system in whichservice modules operating on a plurality of information processingapparatuses connected with a network operate in collaboration with eachother, the system including a monitoring apparatus that is provided witha monitor module monitoring a connection between service modules in thesystem and that has connection management information includingidentifier information for uniquely identifying an informationprocessing apparatus in which a service module is operating in thesystem and connection information including external connectioninformation for the service module to perform communication using anexternal network between the information processing apparatuses andinternal connection information for the service module to performcommunication using an internal network of the information processingapparatus, the method comprising steps of: acquiring, with a connectionmanagement information acquisition unit of the information processingapparatus, the connection management information from the monitormodule; acquiring, with a connection information acquisition unit of theinformation processing apparatus, connection information of acommunication destination service module from the acquired connectionmanagement information; comparing, with a comparison unit of theinformation processing apparatus, the identifier information of theinformation processing apparatus in which the service module isoperating and identifier information of an information processingapparatus in which the communication destination service module isoperating; deciding, with a decision unit of the information processingapparatus, which of the internal connection information and the externalconnection information included in the connection management informationto use based on a result obtained in the comparing step, determining,with a determination unit of the information processing apparatus,whether a connection to the communication destination service module inthe network has been established successfully using the connectioninformation; and notifying, with a notification unit of the informationprocessing apparatus, the monitor module of a result of the connectionto the communication destination service module, wherein a change ismade in the deciding step to use the external connection information, ifa decision is made in the deciding step to use the internal connectioninformation and a decision is made in the determining step that theconnection has failed, and wherein, in the notifying step, the monitormodule is notified that the communication destination service module hasmoved from a host in which the communication destination service moduleis operating, if a connection has been established successfully usingthe external connection information.
 7. The communication methodaccording to claim 6, further comprising steps of: updating, with achanging unit of the monitoring apparatus, upon receiving the result ofconnection notified in the notifying step, the connection managementinformation according to the received result, acquiring, with acorresponding information acquisition unit of the information processingapparatus, corresponding information in which the connection informationand the information processing apparatus have been associated with eachother; and specifying, with a specification unit of the informationprocessing apparatus, another service module connected to a same portand connection information of the other service module from thecorresponding information, wherein, in the notifying step, the monitormodule is notified of the specified connection information.
 8. Thecommunication method according to claim 7, further comprising a step ofsending, with an update notification unit of the monitoring apparatus, anotification to update the internal connection information of theservice module to all service modules, if the connection information hasbeen updated by in the updating step.
 9. A system including a pluralityof information processing apparatuses in which service modules thatoperate in collaboration with a monitoring apparatus provided with amonitor module operate, wherein the monitoring apparatus has connectionmanagement information including identifier information for uniquelyidentifying an information processing apparatus in which a servicemodule is operating in the system and connection information includingexternal connection information for the service module to performcommunication using an external network between the informationprocessing apparatuses and internal connection information for theservice module to perform communication using an internal network of theinformation processing apparatus, and wherein the information processingapparatus comprises: a connection management information acquisitionunit configured to acquire the connection management information fromthe monitor module; a connection information acquisition unit configuredto acquire connection information of a communication destination servicemodule from the acquired connection management information; a comparisonunit configured to compare the identifier information of the informationprocessing apparatus in which the service module is operating andidentifier information of an information processing apparatus in whichthe communication destination service module is operating; and adecision unit configured to decide which of the internal connectioninformation and the external connection information included in theconnection management information to use based on a result obtained fromthe comparison unit, wherein the decision unit decides to use theinternal connection information to perform communication with thecommunication destination service module using the internal network, ifthe comparison unit has determined that the identifier information itemsmatch each other, and decides to use the external connection informationto perform communication with the communication destination servicemodule using the external network, if the comparison unit has determinedthat the identifier information items do not match each other.
 10. Anon-transitory computer-readable medium storing a program that causes acomputer to perform a method comprising steps of acquiring connectionmanagement information from a monitor module; acquiring connectioninformation of a communication destination service module from theacquired connection management information; comparing identifierinformation of an information processing apparatus in which a servicemodule is operating and identifier information of an informationprocessing apparatus in which the communication destination servicemodule is operating; and deciding which of internal connectioninformation and external connection information included in theconnection management information to use based on a result obtained fromthe comparing, wherein a decision is made in the deciding step to usethe internal connection information to perform communication with thecommunication destination service module using an internal network, if,based on the comparing, the identifier information items are determinedto match each other, and a decision is made in the deciding step to usethe external connection information to perform communication with thecommunication destination service module using an external network, if,based on the comparing, the identifier information items are notdetermined to match each other.